FIG. 6.

Inhibition of mitochondrial Ca²⁺ uptake following PV infection decreases cytochrome c release and apoptosis in IMR5 cells. (A) Decrease in cytochrome c release in PV-infected cells treated with RR or DIDS. Cells were mock infected or infected with PV in the presence or absence of 2 μM RR (left) or 10 μM DIDS (right). At the indicated times p.i., cells were collected and subjected to subcellular fractionation. Cytochrome c (Cyt c) was detected in the cytosolic fraction by Western blotting with an anti-cytochrome c antibody. Actin was used as a protein-loading control. Protein levels were determined by densitometry and plotted as ratios relative to actin levels. (B) Decrease in apoptosis in PV-infected IMR5 cells treated with RR or DIDS. Mock- and PV-infected IMR5 cells were left untreated (black) or were treated (gray) with 2 μM RR (left) or 10 μM DIDS (right). At the indicated times p.i., cells were analyzed by flow cytometry after AO staining, and the increase (n-fold) in apoptosis was calculated as the ratio of the percentage of apoptotic PV-infected IMR5 cells to the percentage of apoptotic mock-infected cells. The data shown are the means from three independent experiments. Error bars indicate the standard errors of the means. *, P < 0.05 by Student's t test comparing untreated IMR5 cells to treated IMR5 cells.